Note, not trying to address every last error, just some obvious/easy ones.
```
/usr/local/google/home/jperkins/dev/carbon-lang/common/string_helpers.cpp:200:13: warning: prefer transparent functors 'less_equal<>' [modernize-use-transparent-functors]
auto le = std::less_equal<const char*>();
^
/usr/local/google/home/jperkins/dev/carbon-lang/toolchain/semantics/nodes/function.h:22:45: warning: pass by value and use std::move [modernize-pass-by-value]
Function(ParseTree::Node node, NodeId id, llvm::SmallVector<NodeRef> body)
^
/usr/local/google/home/jperkins/dev/carbon-lang/explorer/ast/declaration.cpp:230:14: warning: static member accessed through instance [readability-static-accessed-through-instance]
return cast<SelfDeclaration>(declaration).name();
^
/usr/local/google/home/jperkins/dev/carbon-lang/explorer/interpreter/type_checker.cpp:1104:33: warning: std::move of the variable 'impl' of the trivially-copyable type 'ConstraintType::ImplConstraint' has no effect [performance-move-const-arg]
impl_constraints_.push_back(std::move(impl));
^
/usr/local/google/home/jperkins/dev/carbon-lang/explorer/interpreter/type_checker.cpp:1145:36: warning: std::move of the variable 'rewrite' of the trivially-copyable type 'ConstraintType::RewriteConstraint' has no effect [performance-move-const-arg]
rewrite_constraints_.push_back(std::move(rewrite));
^
/usr/local/google/home/jperkins/dev/carbon-lang/explorer/interpreter/type_checker.cpp:1156:32: warning: std::move of the variable 'context' of the trivially-copyable type 'ConstraintType::LookupContext' has no effect [performance-move-const-arg]
lookup_contexts_.push_back(std::move(context));
^
/usr/local/google/home/jperkins/dev/carbon-lang/explorer/fuzzing/fuzzverter.cpp:74:42: warning: argument name 'trace' in comment does not match parameter name 'parser_debug' [bugprone-argument-comment]
/*trace=*/false);
^
./explorer/syntax/parse.h:19:17: note: 'parser_debug' declared here
bool parser_debug) -> ErrorOr<Carbon::AST>;
^
/usr/local/google/home/jperkins/dev/carbon-lang/explorer/fuzzing/proto_to_carbon_test.cpp:34:55: warning: argument name 'trace' in comment does not match parameter name 'parser_debug' [bugprone-argument-comment]
const ErrorOr<AST> ast = Carbon::Parse(&arena, f, /*trace=*/false);
^
./explorer/syntax/parse.h:19:17: note: 'parser_debug' declared here
bool parser_debug) -> ErrorOr<Carbon::AST>;
^
/usr/local/google/home/jperkins/dev/carbon-lang/explorer/fuzzing/proto_to_carbon_test.cpp:42:41: warning: argument name 'trace' in comment does not match parameter name 'parser_debug' [bugprone-argument-comment]
&arena, f, source_from_proto, /*trace=*/false);
^
./explorer/syntax/parse.h:25:59: note: 'parser_debug' declared here
std::string_view file_contents, bool parser_debug)
^
/usr/local/google/home/jperkins/dev/carbon-lang/explorer/syntax/parse_test.cpp:27:60: warning: argument name 'trace' in comment does not match parameter name 'parser_debug' [bugprone-argument-comment]
ParseFromString(&arena, "file.carbon", FileContents, /*trace=*/false);
^
./explorer/syntax/parse.h:25:59: note: 'parser_debug' declared here
std::string_view file_contents, bool parser_debug)
^
/usr/local/google/home/jperkins/dev/carbon-lang/migrate_cpp/cpp_refactoring/var_decl.cpp:57:58: warning: string concatenation results in allocation of unnecessary temporary strings; consider using 'operator+=' or 'string::append()' instead [performance-inefficient-string-concatenation]
segments.push_back({type_loc_class, qual_str + " " + range_str});
^
/usr/local/google/home/jperkins/dev/carbon-lang/explorer/fuzzing/ast_to_proto_test.cpp:105:55: warning: argument name 'trace' in comment does not match parameter name 'parser_debug' [bugprone-argument-comment]
const ErrorOr<AST> ast = Carbon::Parse(&arena, f, /*trace=*/false);
^
./explorer/syntax/parse.h:19:17: note: 'parser_debug' declared here
bool parser_debug) -> ErrorOr<Carbon::AST>;
^
```
This does some more work to the run_clang_tidy.py wrapper script, and runs an example pass.
"again" because it's really the proto fuzzer changes that broke it, it had been working before.
"mostly" because there's still an issue within the proto fuzzer that it can't find "port/protobuf.h", i.e. https://github.com/google/libprotobuf-mutator/tree/master/port, but I'm still hesitant to add an include path there.